JP3963532B2 - Cooling device for water-cooled internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention of the present application relates to a cooling device for a water-cooled internal combustion engine with a relatively small displacement, for example, a water-cooled internal combustion engine mounted on a small vehicle such as a motorcycle. The present invention relates to a cooling device for an internal combustion engine.
[0002]
[Prior art, problems to be solved]
Conventionally, in an overhead camshaft type internal combustion engine, the mounting surface of the cylinder head cover to the cylinder head (the split surface of the cylinder head cover) is on the same plane as the cam shaft split surface. For this reason, since the camshaft extension line overlaps the split surface of the cylinder head cover, it is difficult to dispose the cooling water pump on the camshaft extension line so that the cooling water pump is rotationally driven by the camshaft. is there.
[0003]
Therefore, conventionally, the cooling water pump is provided by being attached to, for example, a crankcase or a cylinder head other than the cylinder head cover. For this reason, a dedicated shaft for rotationally driving the cooling water pump is required.
[0004]
Some cooling water pumps are arranged on camshaft extension lines and are rotationally driven by the camshaft (see Japanese Utility Model Publication No. 64-7204). In this case, the camshaft is composed of a cam case and a case. A cam bearing member, which is a separate member, is interposed at a portion penetrating the mating surface portion with the cover. The cooling water pump has a pump case bearing cylinder portion attached to the cam bearing member, It is supported by a cam case.
[0005]
Although it can be said that the cam bearing member is shared, such a member is not necessarily required for mounting and supporting the cooling water pump.
In addition, when such a cam bearing member is used, the cam bearing member passes through the cam case and the case cover, and the cam bearing member is fitted with the case bearing tube portion of the cooling water pump. The number of parts has increased, for example, a liquid sealing means is required at a place.
[0006]
[Means for solving the problems and effects]
The present invention relates to a cooling apparatus for a water-cooled internal combustion engine that solves the above-described problems of the prior art, and the invention described in claim 1 includes a camshaft that drives a valve mechanism of the internal combustion engine. A cooling water pump disposed on the top of the cylinder head and connected to the crankshaft via a transmission mechanism so as to be rotationally driven by the crankshaft, and for sending cooling water to the internal combustion engine; The cylinder head cover is attached to a head cover and is driven to rotate by the cam shaft . A mounting surface of the cylinder head cover to the cylinder head is made lower than a position of the cam shaft, and the axis of the cam shaft is connected to the cylinder head cover. The cooling water pump mounting surface of the cylinder head cover, and the cam axis line of the cylinder head cover. A cooling device of the water-cooled internal combustion engine, characterized in that formed on the outer surface of a portion extending through the side wall of da head cover.
[0007]
The invention described in claim 1 is configured as described above, and the cooling water pump is rotationally driven by the cam shaft, so that a dedicated shaft for rotationally driving the cooling water pump is unnecessary. Further, since the cooling water pump is attached to the cylinder head cover, there is no need for a mounting part in addition to a normal sealing member such as a seal member and bolts used between them and a connecting tool. As a result, the number of parts and the number of processing steps for mounting and driving the cooling water pump can be reduced. Furthermore, the mounting surface of the cylinder head cover to the cylinder head (the split surface of the cylinder head cover) is lower than the cam shaft position so that the cam axis passes through the side wall of the cylinder head cover. By the method, the mounting surface of the cooling water pump can be easily formed on the cylinder head cover.
[0008]
Further, by configuring the invention according to claim 1 as described in claim 2, a chamber (transmission mechanism chamber) that accommodates a transmission mechanism that interlocks and connects the camshaft and the cooling water pump to the crankshaft is effectively used. Thus, a connecting portion between the rotating shaft of the cooling water pump and the cam shaft can be arranged.
[0009]
Moreover, since the mechanical seal of the rotating shaft of a cooling water pump becomes unnecessary by comprising the invention of Claim 1 or Claim 2 like Claim 3, a high level watertightness is acquired. This also shortens the rotating shaft of the cooling water pump and simplifies the structure, so that the cooling device for the water-cooled internal combustion engine can be reduced in size and weight and the cost can be reduced. In addition, the effect produced by using a magnet coupling type pump can be produced.
[0010]
Furthermore, since the partition wall is formed of a resin material by configuring the invention according to claim 3 as described in claim 4, it is possible to reduce the weight and cost of the cooling device of the water-cooled internal combustion engine, Since the partition wall is sandwiched and attached between the cylinder head cover and the pump cover, deformation of the partition wall can be prevented.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, first, an embodiment (Embodiment 1) of the present invention illustrated in FIGS. 1 to 6 will be described.
FIG. 1 is a perspective view showing an outline of a water-cooled internal combustion engine to which a cooling device for a water-cooled internal combustion engine according to Embodiment 1 is applied, and is an overhead camshaft type 4-stroke cycle (commonly referred to as 4 cycles) single-cylinder water cooling. The internal combustion engine 1 is mounted on the body of a small motorcycle (not shown) so as to be positioned between the front and rear wheels.
[0013]
The water-cooled internal combustion engine 1 includes left and right crankcases 2 and 3, a cylinder block 4, a cylinder head 5, and a cylinder head cover 6, and a cylinder of the cylinder block 4 is disposed at the front ends of the crankcases 2 and 3. The cylinder block 4 is overlaid so that the central axis of the hole 7 faces substantially horizontally forward, and further, the cylinder head 5 and the cylinder head cover 6 are sequentially overlaid in front of the cylinder block 4, and the crankcases 2, 3, The cylinder block 4, the cylinder head 5, and the cylinder head cover 6 are integrally coupled to each other.
[0014]
As shown in FIGS. 3 and 4, the mounting surface 65 of the cylinder head cover 6 to the cylinder head 5 (the split surface of the cylinder head cover 6) is another mounting formed at the mounting position of the camshaft 18 described later. The cylinder head cover 6 is lowered by a plurality of bolts 67 in the circumferential direction arranged on the mounting surface 65 portion, being lower than the position of the surface (split surface) 66 (displaced to the side opposite to the cylinder head cover 6) . The cylinder head 5 is integrally coupled.
[0015]
In this way, the axis of the camshaft 18 passes through the side wall of the cylinder head cover 6, and the through-hole on the left side wall in the figure of the cylinder head cover 6 is for mounting a cooling water pump 50 described later. A hole 68 is formed, and the left side wall outer surface 69 is a mounting surface of the cooling water pump 50.
[0016]
3 and 4, a piston 8 is slidably fitted in the cylinder hole 7, and a crankshaft 9 is pivotally supported by the left and right crankcases 2 and 3, Both ends of a connecting rod 12 are pivotally attached to the piston 8 and the crankshaft 9 via a piston pin 10 and a crankpin 11, and when the piston 8 reciprocates, the crankshaft 9 is driven to rotate. It is like that.
[0017]
An intake port 14 and an exhaust port 15 communicating with the combustion chamber 13 at the top of the cylinder hole 7 are formed in the cylinder head 5, and an intake valve 16 and an exhaust valve 17 are respectively connected to the intake port 14 and the exhaust port 15. It is provided so that it can be opened and closed.
[0018]
The intake port 14 is formed in the cylinder head 5 on the inner side from the position where the cylinder head cover 6 is attached to the cylinder head 5 by the attachment surface 65. The cylinder head cover 6 communicates with an intake passage 14 a formed in the cylinder head cover 6 at a position where the cylinder head cover 6 is liquid-tightly attached to the cylinder head 5 by the attachment surface 66. The communication portion is formed on the right end side of the camshaft 18 in the figure.
[0019]
Adjacent the top end of the intake valve 16 and the exhaust valve 17, the top or top of the cylinder head 5, is arranged a camshaft (camshaft) 18, the cam shaft 18, a cylinder head 5 and the cam shaft through a bearing 19 A driven sprocket 21 is integrally fitted to the left-end enlarged diameter portion 18a of the camshaft 18 so as to be sandwiched between the holder 20 and the camshaft 18, and a drive sprocket 22 and a driven sprocket 21 integrated with the crankshaft 9 In addition, an endless chain (transmission mechanism) 23 is stretched over, the camshaft 18 is rotationally driven at half the rotational speed of the crankshaft 9, and the intake valve 16 and the exhaust valve 17 are rotated twice by the crankshaft 9. Each time it is done, it is driven to open and close once.
[0020]
Further, as shown in FIGS. 2, 5, and 6, a radiator 30 that is a heat radiating portion of a cooling device that cools the water-cooled internal combustion engine 1 is disposed above the cylinder block 4. The cooling water tanks 31 and 32 on both sides (the left and right sides are reversed in FIG. 5), the flat radiating fins 33 arranged in parallel in the longitudinal direction and along the vertical plane, and the cooling water tanks 31 and 32 A cooling water conduit 34 (circularly arranged in three rows in the vertical direction and two rows or three rows in the front-rear direction) that passes through the opposing inner wall and the radiating fin 33 in the horizontal direction of the vehicle width. A cooling water inlet / outlet opening 35 is formed in the bottom surface 31a of the tanks 31 and 32 (shown in FIG. 6 and the bottom surface of the cooling water tank 32 is not shown), and a connecting sleeve 38 is provided below the cooling water inlet / outlet opening 35. It protrudes toward and is fitted.
[0021]
The radiator 30 is firmly attached to the cylinder block 4 by bolts 47 that pass through flanges 36 and 37 integral with the bottoms of the cooling water tanks 31 and 32 and are screwed to radiator support brackets 40 and 41 described later. It has been. A cap 39 is detachably fitted to the top of the cooling water tank 31.
[0022]
Further, as shown in FIG. 3, the cylinder block 4 is provided with radiator support brackets 40, 41 projecting to the left and right sides, and cooling water passages 42, 43 provided in the radiator support brackets 40, 41 are provided. The cooling water passage 43 on the right side is communicated with a cylindrical cooling water jacket 44 that surrounds the outer periphery of the combustion chamber 13, and the cylinder head 5 is also provided with a cooling water jacket 45 that matches the opening end of the cooling water jacket 44. The cooling water jackets 44 and 45 are formed in a tapered shape in cross section from the mating surface of the cylinder block 4 and the cylinder head 5 to the back.
The cooling water passage 42 on the left side has a lower end of a connection sleeve 38 fitted into the upper opening thereof, and is connected to the cooling water tank 31 via the connection sleeve 38.
[0023]
Further, as shown in FIGS. 3 and 4, the central portion of the left end enlarged diameter portion 18a of the camshaft 18 is removed from the end surface to form a recess 18b, and a plurality of portions are formed on the inner peripheral surface of the recess 18b. The permanent magnets 24 are disposed at equal intervals in the circumferential direction.
[0024]
The cooling water pump 50 that is rotationally driven by the camshaft 18 includes a partition wall (pump casing) 51, a pump cover 52, and the partition wall 51 and the pump cover 52 in the rotor storage part 51a of the partition wall 51 via the rotation shaft 53. The impeller 54 is rotatably supported by the impeller 54. On the outer peripheral surface of the shaft portion 54a of the impeller 54, the number of poles relative to the permanent magnet 24 of the camshaft 18 is provided via the rotor storage portion 51a of the partition wall 51. A cylindrical permanent magnet 55 is fitted, and a magnet coupling is formed by the permanent magnets 55 and 24, and the impeller 54 of the cooling water pump 50 is magnetically coupled to the camshaft 18, and the cam The impeller 54 is driven to rotate in response to the rotation of the shaft 18.
[0025]
A partition wall (magnetic coupling partition wall) 51 of the cooling water pump 50 is formed of a resin material such as PPS, and a large-diameter portion of the base end of the rotor storage portion 51a is formed on the left side wall of the cylinder head cover 6. The cylinder head cover 6 is fitted into the pump mounting hole 68 and sandwiched between the left side wall of the cylinder head cover 6 and the pump cover 52.
[0026]
As shown in FIG. 6, the suction portion 56 of the cooling water pump 50 communicates with the lower opening 42 a of the cooling water passage 42 of the left radiator support bracket 40 through the communication pipe 46, as shown in FIGS. 3 and 4. As shown in the drawing, the discharge portion 57 of the cooling water pump 50 is communicated with a discharge passage 58 (formed by being closed by the partition wall 51) of the pump cover 52, and the communication of the partition wall 51 communicating with the discharge passage 58 is performed. Both ends of the communication pipe 61 are water-tightly fitted into the passage 59 and the communication passage 60 communicating with the cooling water jacket 45 of the cylinder head 5, and the cooling water in the left cooling water tank 31 of the radiator 30 is The cooling water sucked into the cooling water pump 50 through the cooling water passage 42, the communication pipe 46 and the suction portion 56 of the left radiator support bracket 40 and pressurized by the impeller 54 of the cooling water pump 50 is discharged to the discharge portion 57. From the discharge passage 58, the communication passage 59, the communication pipe 61 and the communication passage 60. Jacket 45 is adapted to be discharged to the cooling water jacket 44.
[0027]
In the communication pipe 61, the area of the end surface exposed to the communication path 60 is larger than the area of the stepped portion that contacts the end surface of the communication path 59. 3 and 4, it is pressed to the left and tightly contacts or fits with the end face and the outer peripheral surface of the communication path 59 to prevent it from coming off.
In the first embodiment, the communication pipe 61 is fitted into a hole 63 formed in the outer peripheral wall of a cylinder head 5 surrounding a transmission mechanism chamber 62 described later on the communication path 59 side. Is also supported in a watertight manner.
[0028]
Further, as shown in FIGS. 3 and 4, an idler sprocket (idle pulley) 25 that meshes with the endless chain 23 is rotatably fitted on the outer periphery of the communication pipe 61, and is closer to the crankshaft 9 than the idler sprocket 25. The idler sprocket 27 is pivotally attached to the cylinder block 4 via the pin 26, and the idler 23 is sandwiched from above and below the crankshaft 9 as shown in FIG. Sprockets 28 and 29 are pivotally attached.
[0029]
As shown in FIG. 6, the communication pipe 61 is disposed in the transmission mechanism chamber 62 in which the endless chain 23 is accommodated, and in the region surrounded by the travel path of the endless chain 23. The idler sprocket 25 fitted on the outer periphery of the communication pipe 61 is also disposed in the same region. As a result, the idler sprocket 25 meshes with the endless chain 23 from the inside of the travel path of the endless chain 23. It is like that.
[0030]
Since this Embodiment 1 is comprised as mentioned above, there can exist the following effects | actions and effects.
When the water-cooled internal combustion engine 1 is in operation and the impeller 54 of the cooling water pump 50 that is magnetically coupled to the camshaft 18 that rotates in response to the operation of the water-cooled internal combustion engine 1 is driven to rotate, the radiator 30 The cooled cooling water in the left cooling water tank 31 is supplied from the cooling water inlet / outlet opening 35 through the connection sleeve 38, the cooling water passage 42 of the radiator support bracket 40, and the communication pipe 46 to the suction portion of the cooling water pump 50. After being sucked into 56 and pressurized by the impeller 54 of the cooling water pump 50, the cooling water jacket 45 is discharged from the discharge portion 57 of the cooling water pump 50 through the discharge passage 58, the communication passage 59, the communication pipe 61, and the communication passage 60. The cooling water in the cooling water jackets 45, 44 is sent from the cooling water passage 43 of the right radiator support bracket 41 into the right cooling water tank 32 and passes through the cooling water conduit 34. Return to the left cooling water tank 31, and the cooling water is cooling water. Circulate in the system.
[0031]
When a small motorcycle (not shown) travels, the traveling wind traveling from the front to the rear passes between the radiation fins 33 of the radiator 30 and is heated by the heated cooling water flowing in the cooling water conduit 34. The cooling water 33 is radiated by the traveling wind, and the cooling water in the cooling water conduit 34 is cooled by the heat radiation of the radiating fins 33.
[0032]
Since the cooling water pump 50 is rotationally driven by the camshaft 18, a dedicated shaft for rotationally driving the cooling water pump 50 is not necessary. In addition, since the cooling water pump 50 is attached to the cylinder head cover 6, there is no need for a mounting part in addition to a normal sealing member such as a seal member or bolt used between them or a connecting tool. As a result, the number of parts and the number of processing steps for mounting and driving the cooling water pump 50 are greatly reduced.
[0033]
The connecting portion (magnet coupling portion) between the rotating shaft 53 of the cooling water pump 50 and the camshaft 18 accommodates an endless chain 23 that interlocks the cooling water pump 50 and the camshaft 18 with the crankshaft 9. Since it is arrange | positioned in the chamber (transmission mechanism chamber) 62, this can be arrange | positioned using space effectively.
[0034]
Furthermore, since the cooling water pump 50 is a magnet coupling type cooling water pump, a mechanical seal of the rotating shaft 53 is not required, and a high level of water tightness is obtained. This also shortens the rotating shaft 53 and simplifies the structure, so that the cooling device of the water-cooled internal combustion engine 1 can be reduced in size and weight and the cost can be reduced. In addition, the effect produced by using a magnet coupling type pump can be produced.
[0035]
Further, since the partition wall 51 is formed of a resin material, the weight of the cooling device of the water-cooled internal combustion engine 1 can be further reduced and the cost can be reduced. The partition wall 51 can be formed by the cylinder head cover 6 and the pump cover 52. Since it is sandwiched and attached, its deformation can be prevented and shape retention can be achieved.
[0036]
Further, the mounting surface (cylinder surface of the cylinder head cover) 65 of the cylinder head cover 6 to the cylinder head 5 is lower than the mounting position of the camshaft 18 so that the axis of the camshaft 18 penetrates the side wall of the cylinder head cover 6. In addition, the mounting surface 69 of the cooling water pump 50 can be formed on the side wall of the cylinder head cover 6 relatively easily by changing the dimensions of the cylinder head cover 6 and the cylinder head 5 in the casting process.
[0037]
Next, another embodiment (Embodiment 2) shown in FIG. 7 will be described.
In the second embodiment, instead of the magnet coupling type cooling water pump 50 in the first embodiment, a normal type cooling water pump 70 is used.
[0038]
For this reason, the base end large-diameter portion of the cylinder portion that accommodates the bearing 74 of the pump casing 71 of the cooling water pump 70 is fitted into the pump mounting hole 68, and the pump casing 71 is located on the left side of the cylinder head cover 6. The side wall and the pump cover 72 are sandwiched and attached. The pump casing 71 is made of metal.
[0039]
The pump rotary shaft 73 is integrally formed with a driven sprocket 21 at a portion that penetrates the bearing portion of the bearing 74, and the end of the camshaft 18 is integrally connected to the driven sprocket 21. .
Although the above points are different from the first embodiment, the other points are not different from those of the first embodiment, and thus detailed description thereof is omitted.
[0040]
Since the second embodiment is configured as described above, the cooling device for the water-cooled internal combustion engine 1 can be easily manufactured by using a normal type cooling water pump 70 that is easily available.
In addition, except for the effect of using the magnet coupling cooling water pump 50, the same effects as those of the first embodiment can be obtained.
[Brief description of the drawings]
1 is a schematic perspective view of a cooling device has been applied the water-cooled internal combustion engine of the water-cooled internal combustion engine according onset bright one embodiment (Embodiment 1).
FIG. 2 is a right side view of FIG.
3 is a cross-sectional plan view cut along line III-III in FIG. 2;
4 is a partially enlarged view of FIG. 3;
FIG. 5 is a front view with a part cut away, taken along line V in FIG. 2;
6 is a partially cutaway left side view of FIG. 1. FIG.
[Figure 7] A cross sectional plan view of the cooling apparatus of the water-cooled internal combustion engine according onset Ming another embodiment (Embodiment 2), which is a similar view as in Figure 4.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Water-cooled internal combustion engine, 2, 3 ... Crankcase, 4 ... Cylinder block, 5 ... Cylinder head, 6 ... Cylinder head cover, 7 ... Cylinder hole, 8 ... Piston, 9 ... Crankshaft, 10 ... Piston pin, 11 ... Crank pin, 12 ... Connecting rod, 13 ... Combustion chamber, 14 ... Intake port, 14a ... Intake passage, 15 ... Exhaust port, 16 ... Intake valve, 17 ... Exhaust valve, 18 ... Camshaft (camshaft), 18a ... Expanded Diameter, 18b ... Recess, 19 ... Bearing, 20 ... Camshaft holder, 21 ... Driven sprocket, 22 ... Drive sprocket, 23 ... Endless chain (transmission mechanism), 24 ... Permanent magnet, 25 ... Idler sprocket (idle pulley), 26 ... Pin, 27, 28, 29 ... Idler sprocket, 30 ... Radiator, 31, 32 ... Cooling water tank, 33 ... Radiating fin, 34 ... Cooling water conduit, 35 ... Cooling water inlet / outlet opening, 36, 37 ... Lange, 38 ... Connection sleeve, 39 ... Cap, 40, 41 ... Radiator support bracket, 42, 43 ... Cooling water passage, 44, 45 ... Cooling water jacket, 46 ... Communication pipe, 47 ... Bolt, 50 ... Magnet coupling type Cooling water pump, 51 ... partition wall (pump casing), 52 ... pump cover, 53 ... rotating shaft, 54 ... impeller, 55 ... permanent magnet, 56 ... suction part, 57 ... discharge part, 58 ... discharge passage, 59, 60 ... Communication path 61 ... Communication pipe 62 ... Transmission mechanism chamber 63 ... Hole 64 ... Communication pipe equivalent part 65 ... Mounting surface (cylinder head cover split surface) 66 ... Mounting surface (split surface) 67 ... Bolt 68 ... Pump mounting hole, 69 ... Cylinder head cover side wall outer surface, 70 ... Cooling water pump, 71 ... Pump casing, 72 ... Pump cover, 73 ... Pump rotating shaft, 74 ... Bearing.

Claims (4)

A camshaft for driving the valve mechanism of the internal combustion engine is disposed at the top of the cylinder head and connected to the crankshaft via the transmission mechanism so as to be driven to rotate by the crankshaft.
A cooling water pump for sending cooling water to the internal combustion engine is attached to a cylinder head cover attached to the cylinder head, and is driven to rotate by the cam shaft;
The mounting surface of the cylinder head cover to the cylinder head is made lower than the position of the cam shaft, and the axis of the cam shaft passes through the side wall of the cylinder head cover.
The cooling apparatus for a water-cooled internal combustion engine, wherein the coolant pump mounting surface of the cylinder head cover is formed on an outer surface of a portion where the cam axis passes through a side wall of the cylinder head cover .   2. The cooling apparatus for a water-cooled internal combustion engine according to claim 1, wherein a connecting portion between the rotating shaft of the cooling water pump and the cam shaft is disposed in a transmission mechanism chamber that houses the transmission mechanism.   The cooling device for a water-cooled internal combustion engine according to claim 1 or 2, wherein a rotating shaft of the cooling water pump is connected to the cam shaft via a magnet coupling.   The cooling device for a water-cooled internal combustion engine according to claim 3, wherein the partition wall of the magnet coupling is formed of a resin material and is sandwiched and attached between the cylinder head cover and the pump cover.

Images